App crashes upon start when touching the screen Android 6.0.0

[hosseinrooholamini]

Hello,
When app starts and i touch anywhere on screen in the first x seconds (anything below 20 seconds from app start) from app start, it crashes.
logcat report:

--------- beginning of crash
10-23 07:59:43.310 23078-23280/com.ldt.musicr E/AndroidRuntime: FATAL EXCEPTION: GLThread 2887
Process: com.ldt.musicr, PID: 23078
java.lang.NullPointerException: Attempt to write to field 'int org.jbox2d.collision.broadphase.DynamicTreeNode.parent' on a null object reference
at org.jbox2d.collision.broadphase.DynamicTree.allocateNode(DynamicTree.java:492)
at org.jbox2d.collision.broadphase.DynamicTree.createProxy(DynamicTree.java:92)
at org.jbox2d.collision.broadphase.BroadPhase.createProxy(BroadPhase.java:90)
at org.jbox2d.dynamics.Fixture.createProxy(Fixture.java:302)
at org.jbox2d.dynamics.Body.createFixture(Body.java:194)
at com.ldt.bubblepicker.physics.CircleBody.initializeBody(CircleBody.kt:65)
at com.ldt.bubblepicker.physics.CircleBody.(CircleBody.kt:57)
at com.ldt.bubblepicker.physics.Engine.build(Engine.kt:54)
at com.ldt.bubblepicker.rendering.java.gltexture.TexturePickerRenderer.initialize(TexturePickerRenderer.kt:83)
at com.ldt.bubblepicker.rendering.java.gltexture.TexturePickerRenderer.onSurfaceChanged(TexturePickerRenderer.kt:71)
at com.ldt.bubblepicker.rendering.java.gltexture.GLTextureView$GLThread.guardedRun(GLTextureView.java:1388)
at com.ldt.bubblepicker.rendering.java.gltexture.GLTextureView$GLThread.run(GLTextureView.java:1123)